The duality of the cell population in a calcifying epithelial odontogenic tumour (CEOT)

Abstract

Ultrastructural findings in a case of CEOT are reported. It was found that the tumour cells consisted of two populations. One population was composed of polyhedral epithelial cells of the type described previously by other authors. These cells showed variation in size and abundant cytoplasm. They contained large numbers of electron-dense bundles of tonofilaments and numerous mitochondria. The other population was a cell having the ultrastructural characteristics of myoepithelial cells. These cells were arranged juxtaposed to the tumour epithelial cells and had very elongated profiles. They showed a lamina densa which was continuous with that in relation to the basal plasma membrane of the tumour epithelial cells and also a large number of hemidesmosomes. These cells also contained large numbers of fine filaments with electron-dense bodies similar to those described in smooth muscle cells. The amyloid-like material was found to consist of two types of structures which are probably related. One type showed sheets of low electron-dense filaments, the other aggregates of lamina densa fragments.

Intraosseous carcinoma of the mandible composed of cells expressing myoepithelial cell‐associated antigens

“…Odontogenic tumors usually do not express myoepithelial markers, with extremely rare exceptions, 24,25 and the present case was convincingly derived from salivary gland components, and differentiated into epidermoid cells, clear cells, mucous cells and myoepithelial cells.…”

So-called Hybrid Odontogenic Tumors: Do they really exist?

“…We realize that papilliferous KA and KA pose similar features but are different entities, as described previously (16,19). Moreover, intraosseous tubulopapillary hidradenoma-like tumor with myoepithelial differentiation should be categorized as papilliferous KA (20), since occurrence of myoepithelial cells has been confirmed in an odontogenic tumor (21). Thus, we have excluded these cases.…”

Current Concepts and Occurrence of Epithelial Odontogenic Tumors: II. Calcifying Epithelial Odontogenic Tumor Versus Ghost Cell Odontogenic Tumors Derived from Calcifying Odontogenic Cyst

“…At the electron microscope level, CEOT epithelial tumor cells consist of polyhedral epithelial cells and myoepithelial-like cells, containing large numbers of electron-dense tonofilament bundles, electron-dense bodies, and fine lamina densa filaments 25. Amyloid-like materials compose fine filament sheets measuring 10-12 nm in diameter and lamina densa fragment aggregates, which are probably secreted by polyhedral epithelial and myoepithelial-like cells.…”